THOUSANDS of protesters looted shops, the police mutinied and the President fled the capital, all indicating that Bophuthatswana, a purportedly sovereign black 'homeland' within South Africa's borders, was on the brink of a coup last night.

Towards midnight about 100 white men in camouflage uniform entered the fray, forming a protective cordon around a looted shopping centre in the capital, Mmabatho. Suggestions that they were members of the South African Defence Force (SADF) sent in to stabilise the situation were denied by the Ministry of Defence in Pretoria.

Speculation that they might be members of the white far-right was fuelled by a report at midnight that a convoy of 20 vehicles full of armed white men in khaki uniforms had been blocked by the South African police at one of the border crossings into Bophuthatswana.

Mr Mangope, who was reported yesterday afternoon to have flown by helicopter to his farm, has led the one-party regime since 'independence' in 1977. He is a member of the right-wing Freedom Alliance, a coalition which includes Mangosuthu Buthelezi's Inkatha Freedom Party and the separatist Afrikaner Volksfront.

Mr Mangope's announcement on Monday that Bophuthatswana would not contest the South African elections next month sparked instant riots, the toll of which so far has been one dead and 70 injured, quite apart from millions of pounds worth of damage to buildings, vehicles and shops.

Mr Mangope, 71, has refused to recognise the legality of the African National Congress, describing it as a 'foreign' organisation although opinion polls show that it enjoys the support of the vast majority of Bophuthatswana's people. Despite repeated efforts in recent weeks by Nelson Mandela to persuade Mr Mangope to accept the inevitable, to see that Bophuthatswana will cease to exist after the elections, ANC supporters have been severely repressed by the local police.

Something had to give and it was Mr Mangope's decision to ignore next month's elections, coming at a time when civil servants had already been on strike for a week demanding reincorporation into South Africa, that precipitated the present crisis.

The day began yesterday with thousands of Mmabatho residents storming and looting the capital's giant Megacity shopping complex. Some policemen responded by firing tear-gas at the crowds. Others went on strike. At mid-afternoon 300 policemen marched on the South African embassy - Pretoria alone in the world recognises Bophuthatswana's sovereignty - where they handed in a petition saying they wanted the 'homeland' to return to South Africa.

'We are suffering, our families are suffering, our houses are being burnt,' a spokesman for the policemen said. 'We are being used as weapons in a political game that we no longer want to play.'

This expression of dissent from the security forces was the signal for thousands of people, many of them carrying ANC banners, to dance down the capital's streets while others in cars, mini-buses and lorries blared their horns and raised clenched fists in victory salutes.

The celebrations appeared to be a trifle premature, however. A question remained as to how far Mr Mangope's Freedom Alliance colleagues, especially those in the far- right Volksfront, might be prepared to go in his defence. Another question was whether President de Klerk might bow to pressure from the ANC and dispatch the army to stabilise the situation.

PRETORIA - South Africa's chief government negotiator set an 'absolute' deadline of this afternoon for Inkatha and the Afrikaner Freedom Front to take part in next month's elections, Reuter reports.